The Persuasive Power of Modality in Political Discourse

The spread of COVID-19 had a profound impact on swaying public discourse and policy priorities during the 2020 presidential campaign. This dissertation aims to examine the extent to which President Joe Biden's deployment of modality in his COVID-19 tweets shaped public sentiment and vaccination rates in the United States. Drawing upon an extensive dataset of 4057 tweets from President Biden's official X account between January 1, 2020, and December 31, 2021, this study applied an integrative content analysis framework, emphasizing the use of epistemic and deontic modal verbs. Analysis revealed prominent themes such as public health measures, community engagement, health consequences, economic fallout, and scientific breakthroughs. Modal verbs like WILL, NEED TO, and HAVE TO emerged as key linguistic tools to build confidence, recommend health protocols, and rally collective effort, molding attitudes and responses to the epidemic. Spearman correlation test showed positive associations between modal usage, social media engagement metrics, and vaccination rates. It also underscored the importance of President Biden’s use of modality in expressing his political positioning.